Skin treatment method and apparatus

ABSTRACT

A method of treating a skin tissue area ( 3 ) having a skin surface ( 5 ) is provided. The method comprises the steps of: deforming the skin tissue area into a deformed shape comprising a plurality of folds ( 17 ) in the skin tissue area; arranging radiofrequency electrodes ( 13 ) in contact with the skin surface on opposite sides of the deformed skin tissue area; and, while maintaining the skin tissue area in said deformed shape, providing a spatially continuous radiofrequency energy flow between the radiofrequency electrodes on opposite sides of the deformed skin tissue area through the deformed skin tissue area, thereby heating at least a portion ( 19 ) of the deformed skin tissue area; and releasing the skin tissue area from said deformed shape, thereby deforming said heated portion ( 19 ) into a wave-shaped zone of heated skin tissue having a depth relative to the skin surface that varies between a minimum and a maximum value in a direction between said opposite sides. Accordingly, an apparatus for treating a skin tissue area ( 3 ) is provided.

CROSS-REFERENCE TO PRIOR APPLICATIONS

This application is a Continuation of U.S. patent application Ser. No.14/397,881 filed Oct. 30, 2014, which is the U.S. National Phaseapplication under 35 U.S.C. § 371 of International Application No.PCT/IB2013/055625 filed Jul. 8, 2013, which claims the benefit of U.S.Provisional Patent Application No. 61/669,187 filed Jul. 8, 2012. Theseapplications are hereby incorporated by reference herein.

FIELD OF THE INVENTION

The present disclosure relates to treatment of skin tissue withradiofrequency (RF) energy, e.g. for rejuvenation, and in particular tofractional RF treatment.

BACKGROUND OF THE INVENTION

Radiofrequency (RF) is a commonly used technology to heat skin tissue totreat wrinkles and skin laxity.

For skin tightening, RF is used to heat below the surface of the skin tocontract collagen. Dermal collagen contracts when it is heated attemperatures between 60° C. and 70° C., and it denatures at highertemperatures, depending upon the duration of the applied heat. Theshrinkage of the tissue can reach tens of percents of the heated tissuevolume, and results in tightening of the skin.

A major disadvantage of the prior art for skin treatments based onuniform heating is that there is a high risk of pain and healingcomplications.

Fractional or pixelated treatment systems are known, which aim toprovide that injured tissue is surrounded by non-injured tissue topromote healing and reduce pain, downtime and risks. US 2006/0047281discloses an example of the use of multi-electrode RF treatment systems,where an electrode is distributed into several elements to heat discretevolumes.

Fractional devices in the prior art are not able to selectively treatsmall localized areas of skin without the use of complex, multiple andrelatively small electrode configurations. Also, they are in general notable to non-ablatively treat skin, causing related pain and the risk ofcomplications.

Improvements in RF treatment of skin are therefore desired.

SUMMARY OF THE INVENTION

A method of treating a skin tissue area having a skin surface accordingto the appended claims is provided. The method comprises the steps of:deforming the skin tissue area into a deformed shape comprising aplurality of folds in the skin tissue area; arranging radiofrequency(RF) electrodes in contact with the skin surface on opposite sides ofthe deformed skin tissue area; and, while maintaining the skin tissuearea in said deformed shape, providing a spatially continuousradiofrequency (RF) energy flow between the radiofrequency electrodes onopposite sides of the deformed skin tissue area through the deformedskin tissue area, and releasing the skin tissue area from said deformedshape, thereby deforming said heated portion into a wave-shaped zone ofheated skin tissue having a depth relative to the skin surface thatvaries between a minimum and a maximum value in a direction between saidopposite sides.

The folds can be any type of undulation or corrugation of the skintissue, ranging from smoothly varying ripples having a number ofprotrusions and depressions in between to one or more fully closed foldswith skin tissue surface portions on opposite sides of the fold touchingeach other.

Thus, a temperature profile having an oscillating depth variationrelative to the surface of the skin tissue area is provided and apattern of surface heated zones and a pattern of deeper tissue heatedzones are created in an efficient manner. The wavelike pattern ofthermal zones in the skin tissue area is provided in a controllablemanner using only two skin-contact electrodes. This facilitatestreatment. Further, by using skin manipulation to distribute the energybetween the dermis and epidermis, leaving certain tissue zonesuntreated, the resulting tissue injury is also distributed and thepresence of untreated tissue promotes healing of injured tissue. Byadjustment of the amplitude and/or “wavelength” of the skin tissuefolds, the treatment depth can be adjusted, e.g. by determination andpossible adjustment of height differences between adjacent relativeprotrusions and depressions. For increased accuracy, such determinationmay take further reference to the relief of the skin tissue area priorto deformation and/or un-deformed skin tissue portions adjacent thedeformed skin tissue area. A suitable apparatus for performing themethod may comprise a profilometer coupled with a memory for storingreference data and a controller for comparing measurement data withstored reference data.

In a particular embodiment, the skin tissue area comprises an epidermislayer and a dermis layer, and an amplitude of at least part of the foldsis arranged such that at least a part of the path defined by thespatially continuous flow of radiofrequency energy between theradiofrequency electrodes and through the deformed skin tissue areaextends through a portion of the dermis layer. Thus, the heating patternextends through the epidermis and dermis that connect through thedermal-epidermal junction. When the treatment is directed also to boththe dermis and the epidermal-dermal junction, then the RF treatment canalso target pigmentation and induce skin textural changes throughneocollagenesis. Heating the dermis can initiate such neocollagenesisand/or neoelastogenesis, heating the epidermal-dermal junction canstimulate the melanocytes and basal cell layer, and heating theepidermis can incite a healing response and also target pigmentation. Asa result, skin rejuvenation and tightening may be improved.

With regard to the dermis, the main disadvantage of the known methodsand devices relying on uniform dermal heating is that the heating isdifficult to control. In particular for mono-polar and bipolar RFconfigurations, the time for heating the tissue can be in themillisecond range and the heat immediately dissipates into thesurrounding tissue. Overheating can lead to patient discomfort, burnsand fat atrophy. The presently provided method overcomes suchdisadvantage by dispersing the heat in the dermis into local treatmentzones, providing slow heating of the dermis compared to known uniformheating systems, which allows for more control.

The step of providing the spatially continuous radiofrequency energyflow between the radiofrequency electrodes and through the deformed skintissue area may comprise heating at least a portion of the deformed skintissue area to a temperature above about 60 degrees Celsius.

Dermal collagen contracts when it is heated to temperatures between 60°C. and 70° C., and it denatures at higher temperatures, which effect candepend on the duration of the applied heat. The shrinkage of the tissuecan reach tens of percents of the heated tissue volume, and results intightening of the skin. To prevent denaturation and/or necrosis, theskin tissue area may be heated to a temperature in a range of 60-70degrees Celsius, and heating to a higher temperature can be prevented.

The step of deforming the skin tissue area into a deformed shapecomprises deforming at least a portion of the skin tissue area using amechanical deformer. Use of a mechanical deformer, e.g. a compressiondevice, facilitates providing and/or maintaining a desired deformedshape reliably, also over prolonged and/or repetitive application of themethod. Such a method may suitably comprise pressing a mask into aportion of the skin tissue area, compressing at least two portions ofskin tissue towards each other and/or applying vacuum suction to atleast part of the skin tissue area, so that the skin may be deformed indifferent ways and according to a desired pattern. The mask suitablycomprises a pattern of protrusions corresponding to the plurality offolds to be formed into the skin tissue area, and application of vacuumsuction suitably comprises applying vacuum suction to one or more vacuumchambers corresponding to the plurality of folds to be formed in contactwith the skin tissue area.

In an embodiment, the step of deforming the skin tissue area isperformed by engaging the skin tissue with the radiofrequencyelectrodes, in particular by bringing the skin surface in frictionalcontact with the radiofrequency electrodes, and displacing theelectrodes towards each other, which facilitates arrangement of theelectrodes around the deformed skin tissue to be treated. In aparticular embodiment, the RF electrodes may be hand-held by a personperforming the treatment, e.g. with RF electrodes imbedded into thefingers of a flexible glove, allowing simultaneous skin manipulation andRF treatment.

The method may further comprise at least one of the steps ofdermabrasion, microdermabrasion, the application of microlesions andouter skin layer resurfacing to promote rejuvenation of the skin tissue.

In accordance with the above, in an aspect, an apparatus for treating askin tissue area having a skin surface is provided. The apparatuscomprises a skin tissue deformer configured to form the skin tissue areainto a deformed shape comprising a plurality of folds in the skin tissuearea and to maintain the skin tissue area in the deformed shape, and anumber of radiofrequency (RF) electrodes, configurable to be in contactwith the skin surface on opposite sides of the deformed skin tissuearea. The apparatus is configured for applying, while maintaining theskin tissue area in said deformed shape, a spatially continuousradiofrequency (RF) energy flow between the radiofrequency electrodes onopposite sides of the deformed skin tissue area through the deformedskin tissue area, and for releasing the skin tissue area from saiddeformed shape after application of the spatially continuousradiofrequency energy flow. Thereby, a portion of the deformed skintissue area is heated such that, when the skin tissue area is releasedfrom said deformed shape, said heated portion is deformed into a zone ofheated skin tissue having a depth variation relative to the skin surfacethat varies between a minimum and a different maximum value in adirection between said opposite sides. Thus, application of fractionalRF treatment is facilitated.

In a particular embodiment, the apparatus comprises a control unitconfigured and arranged to operate the apparatus so as to form the skintissue area into a deformed shape comprising a plurality of folds in theskin tissue area, maintain the skin tissue area in the deformed shape byapplication of the skin tissue deformer, and apply a spatiallycontinuous radiofrequency (RF) energy flow through the deformed skintissue area by application of the radiofrequency electrodes whenarranged on opposite sides of the deformed skin tissue area, and releasethe skin tissue area from said deformed shape by application of the skintissue deformer after application of the spatially continuousradiofrequency energy flow.

In a particular embodiment, the apparatus is configured to heat at leasta portion of the deformed skin tissue area to a temperature above about60 degrees Celsius to cause contraction and/or denaturation of collagenfor tightening of the skin tissue and/or inciting rejuvenation.Preferably, the heating is performed to a temperature in a range ofabout 60-70 degrees Celsius.

The apparatus may comprise a controller configured to operate theapparatus as a function of one or more input signals, e.g. from a userinterface. In an embodiment, the controller may be configured to operatethe deformer.

The apparatus may comprise a thermometer configured to detect atemperature of the skin tissue area and the controller may be configuredto operate the apparatus as a function of one or more signals from thethermometer. This facilitates controlled operation, e.g. providingsafety against overheating and/or including a feedback mechanism. Theapparatus may also include detection of impedance of the skin to givefeedback, for example, on the temperature or the extent of heating.

In order to provide a controlled thermal pattern, the skin tissuedeformer may comprise a mask comprising a pattern of protrusionscorresponding to the plurality of folds to be formed into the skintissue area to define a plurality of adjacent skin tissue folds.Alternatively, the skin tissue deformer may comprise a vacuum systemcomprising one or more vacuum chambers corresponding to the plurality offolds to be formed for creation of skin tissue folds by vacuum suction.The skin tissue deformer may be configured to provide a two-dimensionalarray of skin tissue folds. The spacing of the mask and/or the vacuumpressure may assist in determining the depth of the skin tissue folds.

The skin tissue deformer may comprise a plurality of probes and/orradiofrequency electrodes configured to be brought into frictionalcontact with the skin surface and engage the skin surface, and to bemovable with respect to each other to thereby deform the skin tissuearea into the deformed shape. The probes and/or electrodes may comprisesurface portions providing a high coefficient of friction when incontact with human skin surface, e.g. comprising a rubber and/orroughened contact surface for contacting human skin, and/or comprisingone or more vacuum cups configured to engage the skin by suction. Thus,skin tissue may be pushed and/or pulled in a desired direction to foldthe skin tissue area. Such a deformer facilitates maintaining aparticular deformation for extended periods of time non-invasively. Thedeformer may be adjustable to establish and/or maintain a particulardeformed shape. In an embodiment, the apparatus may comprise a flexibleglove comprising the RF electrodes.

Preferably, the apparatus comprises a cooler, e.g. being configured tocool the skin tissue area to a temperature at or near normal bodytemperature. Thus, a particular thermal gradient in the skin may beprovided and/or a hot feeling may be soothed.

The cooler may comprise a heat sink, such as a radiator with a highthermal conductance and a large surface, convective cooling or chilledgas, possibly in combination with a heat sink, and/or a cryogeniccooling element, but preferred is an active cooling element such as aPeltier-element and/or a refrigerator device, which may be controllablyoperated.

The apparatus may comprise a profilometer, e.g. to provide informationon a height profile of a skin tissue relief feature. The profilometermay be configured to provide one or more signals, such as visualindications and/or signals to be used as input signals, to a controllerconfigured to operate the apparatus as a function of one or more signalsfrom the profilometer, e.g. for adjustment of the deformer to provide adeformation of a desired amplitude and/or wavelength. The profilometercan also provide information on the progress and/or effectiveness of themethod. It is conceivable that a plurality of cycles of heating,cooling, reheating and re-cooling are performed according to the methodpresented herein until a particular skin tissue profile is reached.

The profilometer may comprise a mechanical detector, e.g. with one ormore mechanical probes, an electrical detector, e.g. with one or morecapacitive or resistive sensors and/or an optical detector, e.g. with anoptical reflectance sensor, a camera etc. The profilometer may becoupled with a memory and/or a controller, which may be contained in theapparatus.

The apparatus may be configured for performing dermabrasion,microdermabrasion, and for the application of microlesions and/or outerskin layer resurfacing to the skin tissue area, for which purpose theapparatus comprises, e.g., a mechanical skin tissue perforator, asuitable light source, an ultrasound generator etc. Such apparatusfacilitates inducing skin rejuvenation in addition to providing areformed skin shape to provide a smoother, younger-looking skin.

The apparatus may comprise a controller, possibly having a memory whichmay be programmable, the controller being configured to operate theapparatus as a function of one or more signals from a thermometer, aprofilometer and/or a user interface.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings:

FIGS. 1-4 show steps of a method of treating a skin tissue area;

FIG. 5 is a cross sectional view of skin tissue treated with the method;

FIG. 6 indicates skin tissue treated with fractional RF treatment, forcomparison;

FIG. 7 is a top view of skin tissue treated with the method;

FIGS. 8-12 are thermographs of steps of a method of treating a skintissue area, a corresponding cartoon and a graph of a measurementresult, respectively;

FIG. 13 indicates an embodiment of an apparatus for treating a skintissue area as disclosed herein;

FIGS. 14A-14F indicate mask patterns for use in embodiments of anapparatus;

FIGS. 15A-15B indicate another embodiment of an apparatus for treating askin tissue area as disclosed herein;

FIGS. 16A-16B indicate part of an embodiment of an apparatus with acombination mask and electrode arrangement.

DETAILED DESCRIPTION OF EMBODIMENTS

It is noted that, in the drawings, like features may be identified withlike reference signs. It is further noted that the drawings areschematic, not necessarily to scale and that details that are notrequired for understanding the present invention may have been omitted.The terms “upward”, “downward”, “below”, “above”, and the like relate tothe embodiments as oriented in the drawings. Further, elements that areat least substantially identical or that perform an at leastsubstantially identical function are denoted by the same numeral.

FIGS. 1 and 2 show steps of the method of treating a skin tissue area.FIGS. 1 and 2 show in cross section an apparatus 1 for treating skintissue, which apparatus is placed on a human skin tissue area 3. Theskin tissue area 3 has a skin surface 5, an epidermis layer 7, a dermislayer 9 and a dermal-epidermal junction 11. Below the dermis layer 9further tissue layers are present, which are not shown. The apparatus 1comprises a number of radiofrequency (RF) electrodes 13, arrangeable incontact with the skin surface 5, and a power source 15 connected withthe RF electrodes 13 to apply RF energy to the skin tissue area 3.

In this embodiment, the RF electrodes 13 are configured to be broughtinto frictional contact with the skin surface 5, and to be movable withrespect to each other (indicated with the arrows in FIG. 1 ) to therebydeform the skin tissue area 3 between the electrodes 13 from an initialshape (FIG. 1 ) into a deformed shape (FIG. 2 ) having a plurality offolds 17 in the skin tissue area 3 with relative protrusions anddepressions of a desired amplitude and distance relative to each other,so that the dermal-epidermal junction 11 is folded into an oscillatingwavy shape (FIG. 2 ).

FIG. 3 indicates operation of the RF source 15, with the RF electrodes13 in bipolar configuration and the polarity of the electrodes beingvaried with respect to each other, at high radiofrequency, whilemaintaining the skin tissue area 3 in the deformed shape. The RF energyflow will take the path of least electrical resistance between the RFelectrodes 13 which generally corresponds to the shortest geometricalpath. Thus, a spatially continuous radiofrequency energy flow isprovided from one RF electrode 13 to the RF electrode 13 on the oppositeside of the deformed skin tissue area 3 through the deformed skin tissuearea 3, wherein the RF energy is distributed in a skin tissue zone 19extending at varying depths with respect to the skin surface 5, herealso crossing the dermal-epidermal junction 11. The RF energy isdissipated in the skin tissue zone 19 and heats it. The temperature andspatial extent of the skin tissue zone 19 are related to the power andduration of the applied RF energy.

FIG. 4 shows that, if (the pinching force on) the skin tissue 3 isreleased and the folds 17 are removed, the skin tissue zone 19 that hasbeen heated by the RF energy retains its depth variation relative to theskin surface and the skin tissue zone 19 is accordingly deformed into awave-shaped zone having a depth that varies between a minimum and adifferent maximum value relative to the skin surface in a directionbetween said opposite sides. The depth profile of the heated skin tissuemay be suitably determined with respect to (a maximum of) thetemperature profile perpendicular to the skin surface and/or withrespect to one or more isotherms in the skin tissue. The minimum depthvalue may be substantially zero and the maximum depth value may beseveral millimeters or even over a centimeter for deep skin folds 17,e.g. on a person's belly- or back region.

FIG. 5 shows the skin tissue area 3 of FIG. 4 without the apparatus 1.FIG. 6 indicates an RF energy distribution, and thus the associatedheating pattern, envisioned when using a known fractional RF apparatuswith a relatively dense electrode pattern indicated by means of the boldarrows. The similarity will be striking to the skilled reader. However,as set out above, the RF fields between each pair of adjacent electrodesextend generally to little depth, which depth cannot be accuratelycontrolled. Further, fractional RF systems and the use thereof aresignificantly more complex and delicate as compared to the presentapparatus and method.

FIG. 7 is a schematic top view of the skin surface 5 of a skin tissuearea 3 treated with an embodiment of the presently provided method,indicating a striped pattern of heated (dark) versus cooler (light) skintissue portions, corresponding to superficial and deep portions of theheated skin tissue zone 19, respectively. The temperature of therelatively superficial portions, corresponding to the bottoms of thefolds 17, is indicative of the temperature in the deeper regionscorresponding to the maxima of the folds 17.

FIGS. 8, 9 and 11 show photographs, taken with a temperature-sensitivecamera, of an underarm of a test subject. FIG. 10 is a cartoon of FIGS.8 and 9 . The thermal images were recorded with an FLIR infrared cameraadjusted for the emissivity of human skin (0.98). For this experimentalsystem, bipolar RF electrodes were embedded into fingers of a flexibleglove, allowing simultaneous skin manipulation and RF treatment. FIG. 10shows the underarm 21, the positions of the fingers 23 and theassociated electrodes 13, as well as the folds 17 in the treated skintissue area 3.

FIG. 8 shows skin tissue being pinched between (the fingers 22 carrying)the RF electrodes, with individual folds 17 indicated with arrows, seealso FIG. 10 . The color scale corresponds to a surface temperaturerange of about 29.2-33.5° C. FIG. 9 shows the effect of RF being appliedto the pinched area of FIG. 8 for 2.0 seconds, increasing the averagesurface temperature between the electrodes to 33° C. from about 31° C.FIG. 11 shows the effect of the heating when the pinching pressure isreleased. Generally linear and parallel portions with elevated surfacetemperatures of about 32.7° C. have been created in between theelectrodes. FIG. 12 shows a line profile analysis through the heatedzone as indicated in FIG. 11 , showing the periodic surface temperaturepattern created by the RF energy, comparable to FIG. 7 . This allowscontrolling the operation of the apparatus by employing a suitablethermometer and a controller.

FIG. 13 shows, similar to FIGS. 1-4 , an embodiment of an apparatus 1′that is particularly suitable for skin tissue areas 3 that are noteasily folded by pinching as explained supra, comprising a mechanicaldeformer 25 in the form of a mask comprising a pattern of electricallyinsulating protrusions 27 corresponding to the plurality of folds 17 tobe formed into the skin tissue area 3.

Top views of typical patterns of electrodes 13 and protrusions 27 forforming a one-dimensional array of depressions and folds into the skintissue area 3 to be treated are shown in FIGS. 14A-14D, and FIGS.14E-14F similarly show exemplary patterns of protrusions 27 configuredto deform the skin tissue area 3 into a deformed shape comprising atwo-dimensional array of skin tissue folds 17. The deformer can havepins or edges of any type and/or configuration, e.g. as indicated inFIG. 14A, pins 27 placed in line with RF electrodes 13 and/or elongatededges placed in line with electrodes 13 as in FIGS. 14B-14C. Theelectrodes 13 can have different geometries and can even have a highaspect ratio to cover a significant area of skin. Other patterns,possibly irregularly shaped and/or producing non-equidistant or unevenlydeep skin tissue folds, are equally conceivable.

FIGS. 15A-15B show, similar to FIGS. 1-4 and 13 , a further embodimentof an apparatus 1″ comprising a mechanical deformer 29 comprising aplurality of electrically insulating protrusions 27 connected with avacuum system 31 capable of providing a sub-atmospheric pressure betweenat least some of the protrusions 27. When the deformer 29 is placed incontact with the skin surface 3 and the vacuum system is activated, theskin 3 can be sucked into the areas 33 of negative pressure between theprotrusions 27 and conform to the edges 27 forming the desired folds 17(FIG. 15B). The vacuum pressure may be controlled by employing asuitable profilometer and a controller.

In a preferred embodiment, the insulating deformer portions 27 and RFelectrodes 13 are integrated into a single series of objects, formingfolds 17 by doming of the skin 3 between the objects when they arepressed against the skin surface 5. Such an arrangement is shown in theembodiment of FIG. 16A, the use of which is shown in FIG. 16B in similarfashion as in FIGS. 1-4, 13 and 15A-15B. The shown embodiment,resembling a known shaving device, enables the production of a radialpattern of skin folds 17 and associated heated skin tissue zones 19.

In particular for flexible skin portions, e.g. facial skin, deformingfeatures 27 of a skin deformer may be closely spaced in the millimeteror even sub-millimeter range, and fold amplitudes in the range of about100-300 micrometer, e.g. in a range of about 150-250 micrometer, maysuffice for suitable heating of the dermal-epidermal junction which maybe located at a depth of about 100-200 micrometer from the skin surface.Little separation between the RF electrodes 13 may reduce the RF powerrequired for suitable skin tissue heating.

The presently provided apparatus allows treating much smaller zones oftissue layers than known devices, which serve to treat skin tissue areasof 1-50 cm², typically regions of about 10 cm². However, the use of thepresent apparatus and method is not dictated by inter-electrodedistances and much smaller treatment areas and/or details are possible.For example, folded tissue areas with an interdistance of 0.1-2 cm (withrespect to a direction generally perpendicular to the folds) andelectrode sizes of 0.1-1 cm are possible, resulting in heated tissuezones with typical sizes and/or details of the order of 0.01-2 cm².Also, in apparatus using vacuum pressure a relatively smallunder-pressure may suffice, e.g. 0.01-0.05 atmosphere (negativepressure) with respect to ambient pressure. Other variations to thedisclosed embodiments can be understood and effected by those skilled inthe art in practicing the claimed invention, from a study of thedrawings, the disclosure, and the appended claims. For instance, anytemplate capable of forming at least two skin protrusions can be usedwith both positive and negative pressure vacuum configurations. The folddepth and interfold distance can be varied to influence the treatment.

The deformer or the vacuum surface can be used to conductively cool theskin to enhance the RF heating in deeper tissue layers.

An additional feature of the skin manipulation can be a profilometer,e.g. a contact sensor and/or an optical sensor that facilitatedetermination of whether the amplitude of at least a portion of the skintissue folds, e.g. particular skin tissue protrusions between deformerstructures, are sufficient to trigger application of RF current.

Any type of RF power settings can be used. In one embodiment, afrequency of 1 MHz and a power of 25 W is applied to the skin for asustained period in the range of 1 msec-5 sec.

In any one of the embodiments of an apparatus 1, 1′, 1″ according to theinvention described before, the apparatus may comprise a control unitconfigured and arranged to operate the apparatus so as to form the skintissue area into the desired deformed shape comprising a plurality offolds in the skin tissue area, maintain the skin tissue area in thedeformed shape by application of the skin tissue deformer, and apply thedesired spatially continuous radiofrequency energy flow through thedeformed skin tissue area by application of the radiofrequencyelectrodes when arranged on opposite sides of the deformed skin tissuearea, and release the skin tissue area from said deformed shape byapplication of the skin tissue deformer after application of thespatially continuous radiofrequency energy flow.

It is further noted that in the claims, the word “comprising” does notexclude other elements or steps, and the indefinite article “a” or “an”does not exclude a plurality. A single processor or other unit mayfulfill the functions of several items recited in the claims. The merefact that certain measures are recited in mutually different embodimentsand/or dependent claims does not indicate that a combination of thesemeasures cannot be used to advantage. A computer program may be storedor distributed on a suitable medium, such as an optical storage mediumor a solid-state medium supplied together with or as part of otherhardware, but may also be distributed in other forms, such as via theInternet or other wired or wireless telecommunication systems. Anyreference signs in the claims should not be construed as limiting thescope.

The invention claimed is:
 1. A method of operating an apparatus fortreating a skin tissue area having a skin surface, comprising the stepsof: deforming the skin tissue area into a deformed shape comprising aplurality of folds in the skin tissue area; arranging radiofrequencyelectrodes in contact with the skin surface on opposite sides of thedeformed skin tissue area; and while maintaining the skin tissue area insaid deformed shape, providing a spatially continuous radiofrequencyenergy flow between the radiofrequency electrodes on opposite sides ofthe deformed skin tissue area through the deformed skin tissue area,thereby heating at least a portion of the deformed skin tissue area;providing one or more signals from a profilometer to a controller on aheight profile of said skin tissue area in said deformed shape;adjusting the deformation of said skin tissue area to provide at leastone of a desired amplitude or wavelength responsive to said one or moresignals provided by the profilometer to the controller; and releasingthe skin tissue area from said deformed shape.
 2. The method accordingto claim 1, wherein said released skin tissue area from said deformedshape yields a wave-shaped zone of heated skin tissue having a depthrelative to the skin surface that varies between a minimum and a maximumvalue in a direction between said opposite sides.
 3. The methodaccording to claim 2, further comprising detecting a temperature profileof the wave-shaped zone of heated skin tissue.
 4. The method accordingto claim 3, further comprising determining a depth profile of the zoneof heated skin tissue with respect to a maximum of the temperatureprofile perpendicular to the skin surface.
 5. The method according toclaim 3, further comprising determining a depth profile of the zone ofheated skin tissue with respect to one or more isotherms in the skintissue.
 6. The method according to claim 1, wherein the step ofproviding the spatially continuous radiofrequency energy flow betweenthe radiofrequency electrodes and through the deformed skin tissue areacomprises heating at least a portion of the deformed skin tissue area toa temperature in the range of 60-70 degrees Celsius.